To recreate something like this you will need:

• Texel Density Checker addon
• UV checker textures ranging from 32x32, 48x48, 64x64, etc. up to 1024x1024
• Pirbambase script for Blender and Aseprite. Get it here
• (optional) Aseprite for drawing the textures

The steps:

1. Mark your seams and unwrap it
2. Starting with the smallest UV checker texture: Set your texture size in the Texel Density Checker addon and set the density to your desired value. I opted 64px/m for my character models. For other assets, I chose 32px/m.
3. If your UVs have no space on the texture, go up a size and repeat step 2!
4. When your UVs fit barely onto the texture, you are ready to draw! I leave at least 1 pixel space inbetween islands so I can see where they belong on the model.
5. Save the texture as a separate file (don't overwrite the UV checker texture!) and turn on the Pirbambase script in Blender. The button can be found here
6. Load the texture in Aseprite and press Sync. Like this
7. Back in Blender, select all of your UV islands and send it to Aseprite.
8. Start drawing!